A number of electronic cameras have been recently introduced in the retail still picture camera market. These cameras differ from traditional still cameras because they replace conventional photographic film with a reusable electronic photocell array as the image sensor and an electronic or magnetic memory as the storage medium. The photocell array, located at the focal plane of the camera, generates an array of discrete signal values (pixels) that represent the photographic image. The array of discrete signal values represents the light intensity falling on the image plane at the locations of the photocells that make-up the photocell array. The image can be reconstructed by displaying the set of discrete signal values as a raster array of the pixel intensity on a video display or liquid crystal display (LCD) unit.
Most commercial electronic cameras are directed toward the amateur market and are offered at a range of prices that depend on the features provided. For example, the lowest priced versions typically use optical view finders, such as found on conventional cameras, while higher priced units feature LCD (liquid crystal display) view finders that show the camera operator the image generated by the lens in the photocell array. Because consumers generally prefer the convenience of small cameras, electronic camera manufacturers tend to favor small size even at the expense of inconvenience in manipulating the camera controls. Consequently, the control selector knobs tend to be inconveniently small and are used for multiple purposes which makes these knobs less than optimal for professional use.
Generally, some form of electronic or magnetic digital storage is provided for storing one or more images for later viewing. If an LCD screen is provided for view finding, the stored images can be recalled for display on the camera's LCD screen. Optionally, the stored images may be read out electrically to an external device such as a computer for printing or for archival storage.
More elaborate models offer user-selectable operating modes such as a choice in pixel resolution, black-and-white or color, and various levels of image data compression for increasing the image storage capacity within the camera.
The ability to couple electronic cameras to a computer has resulted in some electronic cameras being used tethered to a computer as a computer peripheral. The computer is used for archival storage and for camera operating mode selection. Selectable operating mode options can include selection of resolution, flash control, shutter speed, and lens aperture. Unfortunately, this tethered configuration results in a photo-imaging system that is not very camera-like but is more like a computer system with a photo-imaging peripheral. The system does not provide the operator with the same “feel” as, or the convenience of, a studio camera to which a professional photographer is accustomed.
The limitations imposed on the professional photographer by currently available electronic cameras may be summarized as follows:                1. inconvenient small control knobs often overloaded with multiple functions;        2. expensive when they include video screen viewfinder, large storage capacity, and easily used manual controls;        3. awkward tethering to a computer; and        4. difficult to set-up, configure, maintain, and use, if tethered to a general purpose computer.        
It is an object of the current invention to overcome the current state-of-the-art limitations by providing a professional-quality camera with the same ease of use as current tripod-mounted view cameras used by professional photographers. Further, it is an object of the current invention to provide some, or all, of the following attributes:                1. the “feel” of a tripod mountable professional camera, as opposed to a computer peripheral;        2. easy to set-up and use;        3. economically priced by taking advantage of developments in the information processing and camera industries;        4. configuration options that include features such as                    a) electronic camera head accepting interchangeable lens;            b) camera parameter control for focus, aperture, and exposure time;            c) LCD view-finder equivalent of ground-glass viewer;            d) high capacity image storage;            e) image processing options including tonality and color correction and enhancement, and image data compression;            f) flexible exposure metering;            g) external input/output communication channel for image data transfer; and            h) ability to apply field upgrades through software loading.                        